var jSetting = new JsonSerializerSettings {NullValueHandling = NullValueHandling.Ignore}; var json = JsonConvert.SerializeObject(response, Formatting.Indented, jSetting);
之前转换的JSON为：
{"header":{"rspCode":"0000","rspDesc":"执行成功","rspErrorMsg":"","rspTime":"2014-03-05T13:40:48.7162196+08:00"},"body":{"order":{"orderid":"S0000001"},"product":null}}
加入代码后转换出来的为：
{"header":{"rspCode":"0000","rspDesc":"执行成功","rspErrorMsg":"","rspTime":"2014-03-05T13:40:48.7162196+08:00"},"body":{"order":{"orderid":"S0000001"}}}